Investigation on the thermal activation of montmorillonite and its application for the removal of U(VI) in aqueous solution

Abstract The application for montmorillonite to deal with toxic metals (including radionuclides) becomes interesting based on its excellent physicochemical properties. In this work, the thermal activation method was utilized to pre-treat montmorillonite before use. The sample was characterized by FTIR, XRD, zeta potential, BET and potentiometric titration to clarify the variation of montmorillonite before and after thermal activation. Batch techniques were used to investigate the sorption ability of montmorillonite to U(VI) under different environmental conditions. The electrical double layer model has been introduced to describe the variation of pre-treated sample as well as the principal mechanism for U(VI) uptake. In addition, the irradiation effects of samples for U(VI) sorption was also investigated. Based on the optimum condition for U(VI) uptake, it can be deduced that the thermally activated montmorillonite has potential application for the removal of U(VI) in wastewater.